Methods and systems to transfer proppant for fracking with reduced risk of production and release of silica dust at a well site

ABSTRACT

Embodiments of methods and systems of transferring proppant for fracking to reduce risk of production and release of silica dust at a well site are provided. An embodiment of a method can include positioning a plurality of containers each having proppant for fracking contained therein onto a conveyor at a well site, downwardly discharging proppant from each respective container of the plurality of containers, funneling proppant from the one or more outlets of each of the plurality of containers through a plurality of conveyor hoppers, receiving proppant onto the conveyor belt, conveying proppant on the conveyor to a chute, and depositing the proppant into the chute for use in a blender or other location at the well site.

RELATED APPLICATIONS

This application is related to and claims priority to, and the benefitof, U.S. Provisional Application No. 62/012,160, filed Jun. 13, 2014,titled “Process and Apparatus for Reducing Silica Exposure During theDelivery of Proppants to a Mine,” U.S. Provisional Application No.62/014,479, filed on Jun. 19, 2014, titled “System and Methods forReducing Silica Exposure at a Well Site,” and U.S. ProvisionalApplication No. 62/114,614, filed Feb. 11, 2015, titled “Methods andSystems to Transfer Proppant for Fracking with Reduced Risk ofProduction and Release of Silica Dust at a Well Site,” each of which areincorporated herein in their entireties by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to reducing the risk of production andrelease of silica dust at a well site during fracking operation. Moreparticularly, the invention relates to methods and systems to enhancetransfer of proppant for hydraulic fracking operations from a containerwhile reducing the risk of production and release of silica dust at awell site.

2. Description of Related Art

Hydraulic fracturing or “fracking” has been used for decades tostimulate production from conventional oil and gas wells. In recentyears, the use of fracking has increased due to the development of newdrilling technology such as horizontal drilling and multi-stagefracking. Such techniques reach previously-unavailable deposits ofnatural gas and oil. Fracking generally includes pumping fluid into awellbore at high pressure. Inside the wellbore, the fluid is forced intothe formation being produced. When the fluid enters the formation, itfractures, or creates fissures, in the formation. Water, as well asother fluids, and some solid proppants, are then pumped into thefissures to stimulate the release of oil and gas from the formation.

By far the dominant proppant is silica sand, made up of ancientweathered quartz, the most common mineral in the Earth's continentalcrust. Unlike common sand, which often feels gritty when rubbed betweenyour fingers, sand used as a proppant tends to roll to the touch as aresult of its round, spherical shape and tightly-graded particledistribution. Sand quality is a function of both deposit and processing.Grain size is critical, as any given proppant should reliably fallwithin certain mesh ranges, subject to downhole conditions andcompletion design. Generally, coarser proppant allows a higher capacitydue to the larger pore spaces between grains. This type of proppant,however, may break down or crush more readily under stress due to therelatively fewer grain-to-grain contact points to bear the stress oftenincurred in deep oil- and gas-bearing formations.

Along with increased access to fossil fuels comes new and addedchallenges for the industry. Exposure to airborne silica has beenidentified by studies as a health hazard to workers conducting somefracking operations. These studies show that workers may be exposed todust with high levels of respirable crystalline silica (“silica dust”)during fracking operations. See Eric J. Esswein, Michael Breitenstein,John Snawder, Max Kiefer & W. Karl Sieber (2013): Occupational Exposuresto Respirable Crystalline Silica During Hydraulic Fracturing, Journal ofOccupational and Environmental Hygiene, 10:7, 347-356. The NationalInstitute for Occupational Safety (“NIOSH”) published a hazard alertalong with OSHA relating to the health hazards particular to thefracking industry. The hazard alert explains that “[t]ransporting,moving, and refilling silica sand into and through sand movers, alongtransfer belts, and into blender hoppers can release dust containingsilica into the air.”

Workers use many tons of proppant at a well site for fracking. Theseworkers risk being exposed to silica dust, which, risks eventuallyleading to a disease called silicosis, or “Potter's Rot.” Silicosis is aform of occupational lung disease caused by inhalation of crystallinesilica dust, and is marked by inflammation and scarring in the form ofnodular lesions in the upper lobes of the lungs. It is a type ofpneumoconiosis, or lung disease caused by the inhalation of dust,usually from working in a mining operation. This dust has other effects,such as contaminating the atmospheric air, creating a nuisance toadjacent landowners, and damaging equipment on the well site. Bloggersand environmental groups have taken a stand against hydraulicfracturing, in part, because of the silica dust created at the wellsite.

Throughout the process of delivering, blending, and mixing proppant at awell site, there is substantial production and release of silica dust. Alarge amount of proppant is delivered by pneumatic tankers. It is thenblown into proppant storage containers. These storage devices can bepre-filled with proppant, either by dumping proppant into storagedevices, or pneumatically conducting proppant to the storage devices,and then delivered to a well site for fracking. Once on the well site,various storage containers have openings in the top which allow air flowto the atmosphere. The flow of air creates a large dust cloud formed ofsilica dust, which blows out of access doors. This especially risksbeing a problem for workers who are looking into the interior of astorage container to monitor the appropriate fill level. As proppant isdispensed from the storage device, additional silica dust is producedand released. As the proppant is dumped into a blender, further silicadust is produced and released. As a result, dust often is produced andreleased at many different stages of the process at a well site.

During this process, if workers are at the well site, they also oftenstand near or directly in the path of a cloud of airborne silica dust.If workers inhale these small particles of silica dust, the each workerrisks particles being embedded deeply into the tiny alveolar sacs andducts in the worker's lungs, where oxygen and carbon dioxide gases areexchanged. The lungs may not be able to clear out the embedded dust bymucus or coughing. Substantial and concentrated exposure to silica dusttherefore risks leading to silicosis.

SUMMARY

Applicants recognized the problems noted above herein and conceived anddeveloped embodiments of systems and methods, according to the presentinvention, to reduce risk of production and release of silica dust at awell site. Embodiments of the present invention generally addressproblems associated with risk of inhalation of silica dust at a wellsite of a fracking operation. More particularly, embodiments of thepresent invention include methods and systems to transfer proppant froma closed container to a chute for delivery to a blender or otherlocation at a well site while reducing the risk of production andrelease of silica dust. By uniquely designing, developing, interfacing,and positioning equipment into a system for transferring proppant,applicants have reduced the production and release of silica dust at awell site of a fracking operation.

In an embodiment, for example, a method includes positioning a pluralityof sealed containers containing proppant for fracking such as by use offorklifts or other heavy machinery onto a conveyor with compartmentsadapted to receive the containers and which overlies one or moreconveyor belts. A plurality of hoppers, e.g., one positioned to underlieeach container when positioned on the compartment of the conveyor,overlays one or more conveyor belts. Once the sealed containers arepositioned on the compartments of the conveyor, the proppant can behydraulically or electrically released from the containers and bedownwardly discharged from each respective container until eachrespective container is substantially emptied of proppant. Afterrelease, in this embodiment, for example, proppant is funneled from theone or more outlets of each of the plurality of containers to andthrough the plurality of hoppers positioned to reduce the risk ofproduction and release of silica dust. Proppant, in turn, guidingly isreceived onto the one or more conveyor belts by a plurality ofpartitions associated with the one or more conveyor belts, e.g., thepartitions can extend upwardly in a space-apart relation from the topsurface of the one or more conveyor belts, such that the plurality ofpartitions is positioned to reduce production and release of silica dustinto the air as proppant is positioned between the plurality ofpartitions and contacts the one or more conveyor belts. The one or moreconveyor belts then convey the proppant to and through a shroudedportion of the conveyor, positioned to reduce the risk of release ofsilica dust, and toward a chute position along an end portion of theconveyor, for example. An embodiment of a chute, for example, can berotatably-positioned to direct the proppant into a blender hopper foruse in a fracking operation, but the chute also can deposit the proppantanywhere on the well site. Once the respective containers aresubstantially emptied of proppant, forklifts or other machinery canremove the empty containers for replacement with containers again beingfilled with and having proppant for fracking at the well site so thatproppant continuously is supplied for and flows towards the chute fordeposit into a blender hopper or other location when in operation.

In another embodiment, for example, a method can include positioning aplurality of sealed containers containing proppant for fracking usingforklifts or other heavy machinery onto a conveyor having compartmentsadapted to receive the containers. The conveyor, in an embodiment, alsocan have a plurality of hoppers that overlays one or more conveyorbelts. Once the sealed containers are positioned on the conveyor,proppant can be downwardly discharged from each respective containeruntil each respective container is substantially emptied of proppant.Proppant, in this process, can be funneled from the one or more outletsof each of the plurality of containers to and through the plurality ofhoppers so as to reduce the risk of production and release of silicadust. Proppant guidingly can be received onto the one or more conveyorbelts by a plurality of partitions associated therewith, such that theplurality of partitions is positioned to reduce production and releaseof silica dust into the air as proppant is positioned on and contactsthe conveyor belt. The one or more conveyor belts then convey theproppant to a blender hopper. Once the respective containers aresubstantially emptied of proppant, forklifts or other machinery removethe empty containers for replacement with containers having proppant forfracking at the well site so that proppant continuously is supplied andflows to the blender hopper during and for fracturing operations.

Embodiments of a system, for example, can include a conveyor positionedat a well site and having compartments adapted to receive eachrespective container of the plurality of containers. The conveyor alsohas one or more conveyor hoppers that align closely with each respectiveoutlet of the plurality of containers to assist in funneling andmetering the proppant flowing from the containers. One or more conveyorbelts are positioned to underlie the one or more conveyor hoppers toreceive proppant as the proppant passes to and through the opening ofeach of the one or more respective conveyor hoppers. The one or moreconveyor belts, for example, can each have a first end, a second end,and a plurality of partitions associated therewith. An embodiment of asystem also can include a shroud positioned to overlie a portion of thesecond end of the one or more conveyor belts thereby to define ashrouded portion of the one or more conveyor belts. The shroud,according to an embodiment thereof, for example, substantially enclosesthe shrouded portion as the one or more conveyor belts convey proppant.The system further can include a chute having an inlet positioned toreceive the second end of the conveyor belt conveying proppant and oneor more outlets positioned such that proppant is deposited into thechute by gravity feed, and proppant, in turn, flows out of the one ormore outlets of the chute to a blender hopper or other location at thewell site.

An embodiment of a system of the invention, for example, can have aconveyor positioned at a well site with compartments adapted to receiveeach respective container of the plurality of containers. The conveyoralso can have one or more conveyor hoppers that align closely with eachrespective outlet of the plurality of containers when positioned on theconveyor and one or more conveyor belts positioned to underlie the oneor more conveyor hoppers to receive proppant as the proppant passes toand through the opening of each of the one or more respective conveyorhoppers. The one or more conveyor belts, for example, each can have afirst end, a second end, and a plurality of partitions associatedtherewith. The system further can include a blender hopper having aninlet positioned to receive the second end of the one or more conveyorbelts thereby to convey proppant by gravity feed.

Embodiments of the system further can include a blender hopper coverpositioned to reduce risk of production and release of silica dust asproppant flows between the one or more outlets of the chute and the oneor more blender hoppers of the one or more blenders at a well site and aforklift positioned at a well site to load and unload each respectivecontainer onto and off of the conveyor by one or more slots. Each of theplurality of containers has one or more slots, for example, positionedadjacent a bottom portion of the respective container to enhance liftingand positioning of each container such as when being lifted by aforklift. The conveyor further can include one or more curtainspositioned on or adjacent to the one or more sides of the conveyor toreduce risk of production and release of silica dust as proppant flowsfrom the plurality of conveyor hoppers to the one or more conveyorbelts.

Embodiments of a system, for example, are adapted and positioned toreduce the risk of production and release of silica dust at a well siteby reducing the fall height for proppant as it flows between onestructure and another, for example, and substantially enclosing eitherthe entire system or portions of the entire system to reduce the risk ofthe escape of silica dust as the system operates. In addition to thepotential health benefits for workers at a well site, and the potentialenvironmental benefits for the areas around a well site, by reducing therisk of production and release of silica dust, embodiments of the systemdescribed herein have a host of other benefits directly to the frackingindustry itself. Well sites frequently are set up on an open plainwithout much protection from the natural elements, and embodiments ofthe system, for example, also are adapted to prevent the wetting ofproppant from rain or other precipitation, or the blowing of proppant bythe wind from the one or more conveyor belts, for example, as proppantmoves through the system. Other aspects of the embodiments of the systeminclude, for example, the portability and stackability of the respectivecontainers having proppant contained therein at a well site, whichdecreases the footprint of the proppant needed at the well site. Theembodiments of the system, for example, also decrease transportationcosts with the ability to transport those containers to a well site byordinary trucks or railcars. Additionally, because the proppant iscontainerized, trucks or rails need not wait to be unloaded at the wellsite. As such, embodiments of the system of the present inventionvirtually eliminate the demurrage of trucks or rails at a well site thatincreased costs and time to provide sufficient proppant to enable thewell site to continuously conduct fracking operations.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing aspects, features, and advantages of the present inventionwill be further appreciated when considered with reference to thefollowing description of embodiments and accompanying drawings. Indescribing the embodiments of the invention illustrated in the appendeddrawings, specific terminology will be used for the sake of clarity.However, the invention is not intended to be limited to the specificterms used, and it is to be understood that each specific term includesequivalents that operate in a similar manner to accomplish a similarpurpose.

FIG. 1 is an environmental perspective view of a well site for frackingusing an embodiment of the system and method according to the presentinvention.

FIG. 2 is a perspective view of a well site for fracking using a priorart system and method.

FIG. 3 is a flow chart demonstrating steps of a method according toembodiments of the present invention.

FIG. 4 is a perspective view of a forklift preparing to position acontainer having proppant for fracking onto a conveyor according to anembodiment of a system and method of the present invention.

FIG. 5A is a fragmented perspective view of a container having proppantfor fracking positioned on a conveyor according to an embodiment of asystem and method of the present invention.

FIG. 5B is an exploded perspective view of FIG. 5A of a container havingproppant for fracking positioned on the conveyor according to anembodiment of a system and method of the present invention.

FIG. 5C is a fragmented perspective view of a container having proppantfor fracking positioned on a conveyor according to an embodiment of athe system and method of the present invention with portions of thecontainer shown in break-away for clarity.

FIG. 6A is a fragmented perspective view of a conveyor hoppersubstantially full of proppant for fracking according to an embodimentof a system and method of the present invention.

FIG. 6B is a fragmented perspective view of a conveyor hopper partiallyfull of proppant for fracking according to an embodiment of a system andmethod of the present invention.

FIG. 6C is a fragmented perspective view of a conveyor hopper withoutproppant according to an embodiment of a system and method of thepresent invention.

FIG. 7A is a fragmented perspective view of a conveyor belt having aplurality of partitions and a plurality of outside walls to conveyproppant according to an embodiment of a system and method of thepresent invention.

FIG. 7B is a fragmented perspective view of an alternative embodiment ofa conveyor belt shown in FIG. 7A, having a plurality of partitions and aplurality of outside walls to convey proppant according to an embodimentof a system and method of the present invention.

FIG. 8A is a fragmented perspective view of a second end of a conveyoraccording to an embodiment of a system and method of the presentinvention with a partial break-away view of the shroud for clarityfurther to show a conveyor belt.

FIG. 8B is a fragmented perspective view of a second end of the conveyoraccording to an embodiment of a system and method of the presentinvention with a partial break-away view of a chute for clarity furtherto show the second end of the conveyor belt depositing proppant into thechute by gravity feed.

FIG. 8C is a perspective view of an operator positioning a chute todeposit proppant into a blender hopper according to an embodiment of asystem and method of the present invention.

FIG. 8D is a perspective view of an alternative embodiment of a secondend of a conveyor without a shroud according to an embodiment of asystem and method of the present invention.

FIG. 9A is a perspective view of a container according to an embodimentof a system and method of the present invention.

FIG. 9B is a front elevation view of a container according to anembodiment of a system and method of the present invention.

FIG. 9C is a perspective view of a container with portions broken awayfor clarity to show lower inner side portions of the container accordingto an embodiment of a system and method of the present invention.

FIG. 9D is another perspective view of a container according to anembodiment of a system and method of the present invention.

FIG. 9E is a bottom plan view of a container according to an embodimentof a system and method of the present invention.

FIG. 10A is a side elevation view of a conveyor according to anembodiment of a system and method of the present invention.

FIG. 10B is perspective view of a conveyor illustrating a containerpositioned above the conveyor according to an embodiment of a system andmethod of the present invention.

FIG. 10C is a side elevation view of an alternative embodiment of aconveyor according to an embodiment of a system and method of thepresent invention.

FIG. 11 is a side elevation view of a conveyor belt underlying aconveyor hopper with break-away portions of a front outer wall of theconveyor belt showing a plurality of partitions according to anembodiment of a system and method of the present invention.

FIG. 12A is a side elevation view of a conveyor having a curtain and ablender hopper cover further to reduce the production and release ofsilica dust at a well site according to an embodiment of a system andmethod of the present invention.

FIG. 12B is a perspective view of a curtain attached to the conveyoraccording to an embodiment of a system and method of the presentinvention.

FIG. 12C is a perspective view of a blender hopper cover positionedbetween a chute and a blender hopper of a conveyor according to anembodiment of a system and method of the present invention.

FIG. 12D is a perspective view of a blender hopper cover of a conveyorand being positioned between a second end of the conveyor and a blenderhopper according to an embodiment of a system and method of the presentinvention.

DETAILED DESCRIPTION

The foregoing aspects, features, and advantages of the present inventionwill be further appreciated when considered with reference to thefollowing description of embodiments and accompanying drawings. Indescribing the embodiments of the invention illustrated in the appendeddrawings, specific terminology will be used for the sake of clarity.However, the invention is not intended to be limited to the specificterms used, and it is to be understood that each specific term includesequivalents that operate in a similar manner to accomplish a similarpurpose.

Embodiments of methods and systems are useful at a well site 30 of ahydraulic fracturing operation. These well sites 30, as shown in FIG. 1,for example, includes a removable floor 32 made of wooden pallets tofacilitate the use of heavy machinery, including one or more forklifts34, cranes 35, or other hydraulic movers, for loading and unloadingcontainers 900 off of the railroad 46 or eighteen-wheeler trucks 44. Therailcars 48 are specially designed to accommodate four containers 900 ina side-by-side arrangement, for example, and containing proppant. Thecontainers 900 are stackable; at the well site 30, containers 900S 1 canbe stacked on top of other containers 900S2 so as to reduce thefootprint of containers 900 at the well site 30 to thereby maximize thespace available. Containers 900 can be stacked up to three-high, forexample, at the well site 30. Because all the proppant 38 iscontainerized, the logistics problems of the prior art where trucks andtrains would demurrage and to unload proppant 38 at the well site 30 iseliminated. The well sites 30 also can include blenders 36 for combiningproppant 38, which is most ordinarily consisting of mined silica sand,but potentially comprising coated or treated sand, ceramic, or bauxite,with fracking fluids generally of a proprietary blend. The well sitealso can include fracking machinery 40 to pump the proppant 38 and otherfracking fluids into the wellbore 42 at high pressure. Embodiments ofsystems, for example, can result in the transfer of fracking sand fordepositing into a blender 36 or other desired location at the well site30 with a reduced risk of the production and release of silica dust 50into the air.

As described in detail in the background section, prior art methods oftransferring fracking sand or proppant 38 resulted in the production andrelease of harmful silica dust 50 at the well site. As shown in FIG. 2,for example, at a well site of the prior art 52, operators or machinescarry out prior art methods for transferring fracking sand or proppantfrom a huge pile of sand 54 on open conveyors 56 into a blender 36 so itcan be useful for the fracking operation. The prior art methods oftransferring proppant 38 at a well site 52 frequently involved aplurality of trucks 44 delivering proppant 38 to a well site 52. Thesetrucks 44, however, often had to wait, or demurrage, for long periods oftime to deliver the load of sand 54 at the well site 32. As can be seenin FIG. 2, the methods used in the prior art result in the significantproduction and release of silica dust 50, which is known to posesignificant health risk to well site workers and have a potentiallynegative effect on the environment.

The flow chart depicted in FIG. 3, and as shown in FIGS. 4, 5C, 6A-6C,7A, and 8A-8C, demonstrates embodiments of a method for transferringproppant 38 for fracking while reducing the risk of production andrelease of silica dust 50 into the air at a well site 30. Usingforklifts 34, cranes 35, or other heavy machinery, operators or machinesposition 100 a plurality of sealed containers 900, each having proppant38 for fracking contained therein, onto a conveyor 1000 adapted toreceive the containers 900 and having a plurality of conveyor hoppers600 that overlay one or more conveyor belts 700. These containers 900can be positioned 102 in a side-by-side arrangement, or positioned 104adjacent each other on the conveyor 1000. This positioning can, forexample, maximize the amount of proppant 38 that can be transported tothe wellbore 42 in the shortest amount of time possible for efficiency,while still reducing the risk of production and release of silica dust50.

Operators or machines utilize hydraulics or electronics to selectivelyopen a series of gates, for example, a flow gate 932 at the bottom 906of each respective container 900, and a conveyor hopper gate 612 at thebottom 608 of each respective conveyor hopper 600, that control a seriesof openings, for example, one or more outlets 924 of a container 900 andone or more controllable openings 610 of a conveyor hopper 600, throughwhich the proppant 38 is funneled. The close positioning and design ofthe containers 900 and conveyor 1000, for example, minimize the risk ofproduction and release of silica dust 50 as the proppant 38 is funneledto the conveyor belt 700. For example, once the sealed containers 900are positioned on the conveyor 1000, operators or machines downwardlydischarge 110 the proppant 38 from each respective container 900 untileach respective container 900 is substantially emptied of proppant 38.Proppant 38 then is funneled 120 from the one or more openings 924 ofeach of the plurality of containers 900 to and through the plurality ofconveyor hoppers 600 that are adapted and positioned to reduce the riskof production and release of silica dust 50.

Proppant 38 is received 130 onto the conveyor belt 700 by a plurality ofpartitions 712 associated therewith, such that the plurality ofpartitions 712 is positioned to reduce production and release of silicadust 50 into the air as proppant 38 contacts and is carried by theconveyor belt 700. These plurality of partitions 712, for example,include a plurality of fingers 714 spaced-apart from each other on thetop surface 702 of the conveyor belt 700. The plurality of partitions712 further can include outside walls 716 of the conveyor belt. Theplurality of partitions 712, therefore, can guidingly accept proppantonto the conveyor belt 700 while, for example, breaking up any clumps ofproppant 38, if any, that may pass through each respective conveyorhopper 600, and further reduce any production and release of silica dust50 as the proppant 38 contacts the conveyor belt 700. The conveyor belt700 is also closely positioned beneath or adjacent the bottom portion608 of each conveyor hopper 600 to further reduce the fall-height forthe proppant 38 to a matter of inches, for example, as it contacts andis transported by the conveyor belt 700.

The one or more conveyor belts 700 then conveys 140 the proppant 38 toand through a shrouded portion 802 adapted and positioned to reduce therisk of release of silica dust 50 to a chute 822. This shrouded portion802 can be optionally omitted if the conveyor 1000 is designed todirectly deposit proppant 38 from the conveyor belt 700 into a blenderhopper 810, for example, as shown in embodiments described herein,including FIG. 8D, for example. The conveyor belt 700 travels in acontinuous loop around a designated path controlled by rollers 708 andpowered by one or more diesel or electric engines 710. According to anembodiment, the conveyor belt 700 can be nearly enclosed or fullyenclosed as it conveys the proppant 38 to the chute 822. In anembodiment, for example, proppant 38 can be protected from the naturalelements of rain and wind, for example, to avoid deteriorating thecondition of the proppant 38 and to further minimize the production andrelease of silica dust 50 onto the well site 30. Proppant 38 can bedeposited 150 into the chute 822 by gravity feed 812 as the conveyorbelt 700 turns about the rollers 708 of the conveyor 1000. This chute822 can be designed and rotatably-positioned to direct the proppant 38into a blender hopper 810 for use in the fracking operation, but thechute 822 could deposit the proppant 38 anywhere on the well site 38.The chute 822 can have handles 823 for an operator 806 at a well site 30to direct proppant 38 from one or more outlets 826 of the chute 822 viagravity feed 812 into one or more blender hoppers 810, for example.

Once the respective containers 900 are substantially emptied of proppant38, forklifts 34, cranes 35, or other machinery can remove 160 the emptycontainers 900 for replacement with containers 900 having proppant 38for fracking at the well site 30 so that proppant 38 is continuouslyflowing toward the blender hopper 810 or other location at the well site30 while in operation. Containers can be stacked 900S1, 900S1 at thewell site 30, for example, up to three-high to be refilled with proppantor transported off the well site 30 to be refilled with proppant 38. Thecontainerized aspects of the embodiments of the invention allow for thecontinuous flow of proppant 38 to the wellbore 42 at a well site 30while the conveyor 1000 is in operation.

Embodiments of containers 900, for example, can be adapted for andpositioned to reduce the risk of production and release of silica dust50 at a well site 30. As depicted in FIGS. 9A-9E, each respectivecontainer 900 is in the nature of a box with an exterior frame 902having two sets of parallel sides 901A1, 901A2, 901B1, 901B2 that areeach perpendicular to a top 904 and a bottom 906. The container 900 canbe a ten-foot ISO container. The container can have a ladder 903 for anoperator to climb to the top 904 of the container 900 and inspect thecontents within the container 900, for example. This means that thecontainer 900 can have a length of ten feet, a width of eight feet, anda height of eight-and-a-half feet, for example. The height can also benine-and-a-half feet. This embodiment, for example, can holdapproximately twenty-three tons of proppant 38 (approximately43,000-48,000 lbs.), in each such container 900. The containers 900 aredesigned to drain the proppant 38 contained therein in under twominutes, or at a rate of 25,000 pounds per minute. Because of the weightand magnitude of the proppant 38, the container 900 is made of steel orother similar material and the exterior frame 902 is cage-like orlattice-like and useful for the structural support and positioning ofeach container 900 onto the compartments 1002 of the conveyor 1000 thatare adapted to receive each respective container 900. The frame 902 alsoincludes a plurality of slots 901, including, for example, two slots901, by which a forklift 34 can lift and position the plurality ofcontainers 900 on the conveyor 1000.

The top 904 of each container 900 has an inlet 905 that may be openedand closed by a door 914, hatch, gate, or other closing mechanism. Thisdoor 914 can provide a seal, or an air-tight and water-tight connection,to the container 900, as it is preferable for the proppant 38 to remainsubstantially dry. Although proppant 38 can flow through embodiments ofthe system with some degree of moisture content, it is preferable toprevent the clumping of proppant 38 caused by moisture. The door 914 isalso important to prevent the escape of silica dust 50 from the proppant38 contained therein before and during the transfer of proppant 38 fromthe containers 900 through an embodiment of a system. A person havingskill in the art can grasp the available options to design, affix, orattach a door 914 to accomplish this sealing function.

The container 900 is made of steel or other similar material. As viewedfrom the outside of the container 900, and as shown in FIGS. 9A-9E, thebottom portion 916 of the container 900 is open and looks like a funnelstructure 918 enclosed within an open external frame 902. Referring toFIG. 9D, the external frame 902 form's a bottom 906 that comprises aplanar surface 920 perpendicular to the two pairs of parallel sides901A1, 901A2, 901B1, 901B2. Referring to FIG. 9B, The bottom portion 916is open to allow the cylindrical or angular funnel structure 918 todispense the proppant 38 in the container 900 according to embodimentsof methods and systems. Embodiments having the bottom portion feature916 can be useful in international shipping. During the course ofinternational shipping, for example, it is important to avoid closedspaces within such a container 900. The exposure of the funnel shape 918in the bottom portion 916 of the container 900 will allow inspectors tohave visual access to the area adjacent the funnel shape 918.

As can be seen in from the partial break-away view of a container 900shown in FIG. 9C and the series of cross-section views of the containerin FIGS. 5A-5C, the funnel structure 918 comprises a plurality ofinclined lower inner portions 922 of the container 900. The plurality ofinclined lower inner portions 922 is roughly in the center 923 of thebottom 906 and has an opening or openings 924. The plurality of inclinedlower inner portions 922 is designed to ensure that when proppant 38 isdirected out of the container 900, proppant 38 flows from the container900 until it is substantially empty. The inclined lower inner portions922 of each respective container 900 are inclined inwardly from innerwalls 926 of the respective container 900 toward a bottom 906 of thecontainer at an angle 928 of about 31 degrees to about 37 degreesrelative to a horizontal plane 920 of the bottom of each respectivecontainer 900 when each respective container 900 is level. Experimentshave shown that this angle 928 is particularly effective in the fullrelease of proppant 38 from the interior of the container 900. Anyremaining proppant 38 in the container 900, for example, could riskposing a threat to workers in the vicinity of the container 900 duringtransport of the container 900 to another location. Additionally,because the plurality of inclined lower inner portions 922 is inclinedin this respect, proppant 38 does not rush directly out of the interior,as it may otherwise do. Rather, proppant 38 flows along the plurality ofinclined lower inner portions 922, creating a sink hole or a funnel 930,toward the one or more openings 924 so as to reduce the production andrelease of silica dust 50 as proppant 38 flows from the container 900.

A flow gate 932 is positioned within tracks 933 located on the bottom906 over or adjacent the opening or openings 924 of the inclined lowerinner portions 922 of each respective container 900, as shown in FIGS.9D-9E. The flow gate 932 can be planar and is designed to cover theopening or openings 924. The flow gate 932 may be a metering gate oranother structure capable of controlling the flow of proppant 38 fromthe opening or openings 924 that is known to a person skilled in theart. The flow gate 932 includes a handle 934 positioned outwardly fromthe flow gate 932. Referring to FIGS. 5A-5C, in an embodiment of thesystem, for example, the handle 934 of the flow gate 932 is designed tosit in the one or more forks 500 of the conveyor 1000, such that anactuator 502 connected to the forks 500 can move the flow gate 932 toenhance opening or closing the one or more openings 924 of the container900. For a container 900 of this size and magnitude that holdsapproximately two tons of proppant 38, the actuator 502 can behydraulically- or electrically-controlled to enhance opening and closingof the flow gate 932. If hydraulics are used, for example, a pluralityof hydraulic pressure hoses 503 can connect the actuator to the one ormore engines 710. If electronics are used, for example, a plurality ofwires 505 can be used to connect the actuator to the one or more engines710. Wireless connections are also contemplated. A person of skill inthe art would understand the various connections to engines 710 andcontrols 1017 available for powering the actuator 502. The flow gate 932can be controlled remotely via the interne, or locally on the well site30, either by an operator or a machine. This flow gate 932 also controlsthe rate at which proppant 38 flows from the container 900 to reduce theproduction and release of silica dust 50 associated with the proppant 38into the air at the one or more openings 924.

The containers 900 described herein are adapted to fit onto compartments1002 of a conveyor 1000 adapted to receive the containers 900 thereon.As shown in FIGS. 10A, 10B, and 12B, an embodiment of a conveyor 1000 ofembodiments of methods and systems includes a frame 1004 with a top1006, a bottom 1008, two sides 1010A & 1010B, a first end 1012, and asecond end 1014. The conveyor 1000 is made of steel or other similarmaterial. It may be approximately forty feet in length, eight-and-a-halffeet in width, four feet in height, and having wheels 1016 and controls1017 on the first end 1012, the second end 1014, or both, but including,for example, on the second end 1014, and a trailer hitch 1018 on thefirst end 1012, the second end 1014, or both, but including, forexample, on the second end 1014, such that an operator could attach theconveyor 1000 to the cab of an eighteen-wheeler truck 44 and pull theconveyor 1000 on a highway. The size of the conveyor 1000 is designed tobe at or below the dimensions permitted by law for trailers of trucks44, so the dimensions may be adjusted as dimensions change for safehighway travel. The frame 1004 must be able to support up to severaltons of proppant 38 housed in a plurality of containers 900. Theconveyor 1000 has one or more hydraulic or electric lifts 1019 to makesure that the frame 1004 is level because the well site may have unevenground. If hydraulics are used, for example, a plurality of hydraulicpressure hoses 1021 can connect the lifts 1019 to the one or moreengines 710 and controls 1017. If electronics are used, for example, aplurality of wires 1023 can be used to connect the lifts 1019 to the oneor more engines 710. Wireless connections are also contemplated. Aperson of skill in the art would understand the various connections toengines 710 and controls 1017 available for powering the lifts 1019. Theone or more lifts 1019 also decrease the risk that the conveyor 1000will tip over or become unstable on the well site 30.

As shown in FIG. 10B, the top 1006 of the frame 1004 comprises a topsurface 1020 that is adapted to receive embodiments of the containers900 described herein. The top surface 1020 has one or more compartments1002, each adapted to receive one or more containers 900, an example ofwhich can be seen in FIG. 6C. In an embodiment, for example, theconveyor 1000 has three to five compartments 1002 to receive three tofive containers 900 having proppant 38 for fracking. As shown in FIG.10B and FIG. 12A, the top surface 1020 can have four compartments 1002to receive four containers 900 having proppant 38 for fracking. In thesame embodiment, for example, the four containers 900 are positioned onthe conveyor 1000 such that each container 900 has either one or bothparallel sides 901A1 and 901A2 adjacent the either one, or both parallelsides 901A1 and 901A2 of another container 900, the top 904 and bottom906 of each container 900 is perpendicular to the top surface 1020 ofthe conveyor 1000, and the top 904 and bottom 906 of each container 900is overlaying the conveyor belt 700 positioned below the top surface1020 of the conveyor 1000. In this embodiment, for example, eachcontainer 900 is positioned in a line such that the proppant 38contained within each container 900 will flow out of each container 900onto one or more conveyor belts 700. In another embodiment, theplurality of containers 900 are positioned in a side-by-side arrangementon the top surface 1020 of the conveyor 1000 overlaying one or moreconveyor belts 700.

As can be seen in FIGS. 4, 5A, 5C, 6A-6C, the one or more compartments1002 of the conveyor 1000 can include corners 1022, tracks, lock-and-keyconnections, and female-and-male connections, for example. These corners1022, for example, can be made of steel or other similar material. Thecontainer 900 need not fit tightly onto each compartment 1002. Instead,for example, the corners 1022 need only to guide the container 900 intoposition onto the compartment 1002 such that the container 900 will notfall off of the conveyor 1000. Alternatively, the container 900 may fittightly on the compartment 1002. The sheer weight of the container 900,however, would usually prevent the container 900 from moving once it ispositioned on the compartment 1002, even without any such corners 1022,and the compartment 1002 need not have any such corners 1022 asdescribed herein. In an embodiment of a system, and as shown in FIG. 4,for example, a forklift 34, crane 35, or other heavy machinery lifts acontainer 900 having proppant 38 up and over the top of the respectivecompartment 1002 of the conveyor 1000, comprising steel corners 1022extending vertically from each respective corner of each respectivecompartment 1002 of the conveyor 1000, and lowers the container 900having proppant 38 into place onto the conveyor 1000. The corners 1022of the compartment 1002 guide the container 900 into place. Referring toFIG. 5C, the respective corners 1022 of the compartments have aplurality of load cells 1024 for determining the weight of eachcontainer 900 on each respective compartment 1002 of the conveyor 1000.In an embodiment of the present invention, for example, a load cell 1024is positioned in each of the four corners of the compartment 1002. Theseload cells 1024 inform an operator or machine how much proppant 38 isleft in the respective container 900 by its weight so the operator ormachine knows when to replace the respective empty container 900 withanother container 900 filled with proppant 38 at a well site 30. Therespective load cells 1024 are in electric or wireless communication viawires 1025 or wirelessly with a light 1026 to indicate to the operatoror machine that the container 900 is positioned properly onto thecompartment 1002. When a container 900 is positioned properly on thecompartment 1002, for example, the light 1026 may change from red togreen, for example. It should be understood that a forklift 34 need notlift the respective container 900 up and over the corners 1022 of thecompartment 1002 of the conveyor 1000 if alternative structures are usedinstead of corners 1022. In this way, the forklift 34 could, forexample, lift the container 900 up to the height of the top surface 1020of the conveyor 1000 and slide the container 900 onto the respectivecompartment 1002.

The conveyor 1000, having a plurality of compartments 1002 adapted toreceive containers 900, also can have a plurality of openings 1028 inthe top surface 1020 of the conveyor 1000. The plurality of openings1028 is positioned beneath the respective plurality of containers 900 onthe conveyor 1000 such that proppant 38 flowing from each respectivecontainer 900 will pass through each respective opening 1028. Eachopening 1028 has one or more forks 500 positioned above or adjacent theopening or openings 1028, the one or more forks 500 adapted to receive ahandle 934 of a flow gate 932 of a container 900 to engage, contact, orcommunicate with the corresponding handle 934 of the flow gate 932 ofthe container 900, as shown in an embodiment depicted in FIGS. 5A-5C and10C. The handle 934 of the flow gate 932, the one or more forks 500, orboth, are in electric or wireless communication with the light 1026,along with the respective load cells 1024 of the corners 1022 via wires1025 or wirelessly, to indicate to an operator or machine that thecontainer 900 is in proper position when the handle 934 of the flow gate932 is aligned or situated in the one or more forks 500 of thecompartment 1002. The variety of connections or contacts to secure orplace the container 900 onto the top surface 1020 of the conveyor 1000,such that the actuator 502 can operate the flow gate 932 of thecontainer 900, will be apparent to a person having skill in the art.

Embodiments of the conveyor 1000, for example, also can include aplurality of conveyor hoppers 600 positioned adjacent or beneath theplurality of openings 1028 in the top surface 1020 of the conveyor 1000.The plurality of conveyor hoppers 600 is positioned such that whencontainers 900 are placed onto the conveyor 1000, each respectiveconveyor hopper 600 is beneath the flow gate 932 of the one or moreopenings 924 of each respective container 900. As shown in FIGS. 5A-Cand FIGS. 6A-6C, each respective conveyor hopper 600 can include aplurality of inclined sides 602 to form a receptacle or funnel structurefor proppant 38 to pass into and through as proppant 38 is dischargedfrom each respective container 900 when in operation. The plurality ofinclined sides 602 can include a pair of short sides 604A1, 604A2 and apair of long sides 604B1, 604B2. Based on experimental results, theshort sides 604A1-A2 can have a funnel angle 605A or slope ofapproximately 35 to 40 degrees relative to a horizontal plane 1020,including, for example, 38 degrees, and the long sides 604B1-B2 can havea funnel angle 605B or slope of approximately 28 to 33 degrees relativeto a horizontal plane 1020, including, for example, 31 degrees, tomaximize the capacity of the conveyor hopper 600 and the flow ofproppant 38 from the conveyor hopper 600.

The conveyor hopper 600 has a top portion 606 and a bottom portion 608,and the bottom portion 608 can include one or more controllable openings610. The top portion 606 of the conveyor hopper 600 can be in the sameplane, above it, or below the top surface 1020 of the conveyor 1000. Thetop portion 606 of the conveyor hopper 600 can be in the same plane orhigher than the top surface 1020 of the conveyor 1000, as can be seen inFIGS. 10B, 10C. Each conveyor hopper 600, for example, can be zero totwo inches below the respective flow gate 932 of the one or moreopenings 924 of the bottom of each container 900. In this embodiment,for example, the distance the flowing proppant 38 has to pass from theone or more openings 924 of the container 900 into the conveyor hopper600 is minimized to reduce the risk of production and release of silicadust 50. This close proximity further limits the risk of exposure tosilica dust 50 by workers at the well site 30. The bottom portion 608 ofthe conveyor hopper 600 also can include one or more controllableopenings 610. The one or more controllable openings 610 can include ahopper gate 612. The hopper gate, for example, can be made of steel orsimilar material, and can be formed in the shape of an inverted “V” orother shape that facilitates the flow of proppant 38 through the bottomportion 608 of the conveyor hopper 600. The hopper gate 612 can beconnected to a hopper gate actuator 613 that can be optionallyhydraulically- or electrically-controlled to enhance opening and closingof the one or more controllable openings 610 of the conveyor hopper 600.If hydraulics are used, for example, a plurality of hydraulic pressurehoses 614 can connect the hopper gate actuator 613 to the one or moreengines 710 and controls 1017. If electronics are used, for example, aplurality of wires 616 can be used to connect the hopper gate 612 to theone or more engines 710 and controls 1017. Wireless connections are alsocontemplated. A person of skill in the art would understand the variousconnections to engines 710 and controls 1017 available for powering thehopper gate actuator 613. In the embodiments shown in the series fromFIGS. 6A to 6C, for example, proppant 38 is controllably discharged fromthe conveyor hopper 600 so that there is no excess proppant 38discharged at any one time. This embodiment prevents the creation of acloud of silica dust 50 in the area of the conveyor belt 700, whilemaximizing the efficiency of the delivery of proppant 38 onto theconveyor belt 700.

Embodiments of methods and systems, for example, also can include one ormore conveyor belts 700. Each respective conveyor belt 700 has a topsurface 702, a bottom surface 704, and two sides 706A, 706B. Eachrespective conveyor belt 700 is manufactured as one long piece, or iszippered together to form one long piece. Each respective conveyor belt700 has a first end portion 705 and a second end portion 707. Eachrespective conveyor belt 700 is suitably wound around rollers 708 totravel a desired path. Each respective conveyor belt 700 is powered byone or more engines 710. These engines 710 can be diesel, electric, or acombination of the two. Diesel engines 710 have been used in the filedfor many years and are reliable in remote locations. Electric engines710, however, are cleaner to use but may require, for example, anon-site generator, batteries, or access to electric power to run. Theindustry, however, is moving towards cleaner power sources, and thevarious engines 710 available will be known to a person of skill in theart. As shown in FIGS. 7A-7B and 8A-8D, each respective conveyor belt isadapted to reduce the risk of production and release of silica dust 50as proppant 38 guidingly falls from the plurality of conveyor hoppers600 to the one or more conveyor belt 700. The respective one or moreconveyor belts 700 can include a plurality of partitions 712.Embodiments of the plurality of partitions 712 can include a pluralityof fingers 714 and an outside wall 716 on each side. Each respectiveconveyor belt 700 can be manufactured to include, or integrate, theplurality of fingers 714 and the outside walls 716. Alternatively, theplurality of fingers 714 and the outside walls 716 can be connected to atop surface 702 of a conveyor belt using commercially-acceptableadhesive.

Referring to FIG. 11, the plurality of fingers 714 of the conveyor belt700 connect to and extend upwardly from a top surface 702 toward theconveyor hopper 600 when positioned to underlie the conveyor hopper 600,and each of the plurality of fingers 714 is spaced-apart from anotherone of the plurality of fingers 714 so that the top surface receives theproppant 38 thereon and between the plurality of fingers 714. Theplurality of fingers 714 are perpendicular or near-perpendicular to thetop surface 702 of the one or more conveyor belts 700. The plurality offingers 714 are closely-spaced from one another, including from betweenone and four inches apart from one another. The plurality of fingers 714may be arranged in a regular pattern or an irregular pattern on the topsurface 702 of the respective conveyor belt 700. The arrangement orpattern of the plurality of fingers 714 need only to fulfill thefunction of the plurality of fingers 714, which is, for example, toseparate out the proppant 38 and break up the clumps of proppant 38, ifany, falling from the conveyor hopper 600. The plurality of fingers 714also is useful in guiding the proppant onto the top surface 702 of theconveyor belt 700 to reduce the production of silica dust 50. As can beseen in the embodiments shown in FIGS. 7A and 7B, for example, theplurality of fingers 714 may be cylindrical, angular, or flat. Eachrespective finger 714 has a top 718 that may be flat or rounded. Theplurality of fingers 714 each may have a top 718 that is flat because,as the conveyor belt 700 is running, the vibrations from the engine orengines 710 do not permit the proppant 38 to remain on the top 718 ofthe plurality of fingers 714. Rather, the proppant 38 will fall betweenthe plurality of fingers 714 to the top surface 702 of the one or moreconveyor belts 700, as is shown in FIG. 7A.

Each side 706A, 706B of the one or more conveyor belts 700 has anoutside wall 716 positioned at or near the margin or edge of therespective side 706A, 706B. The outside wall 716 can be in a continuous“S” shape to permit the conveyor belt 700 to compress and flex aroundrollers 708 as the conveyor belt 700 is moving to prevent the escape ofsilica dust 50. The outer wall 716 also prevents proppant 38 fromspraying or falling out the sides 706A, 706B of the conveyor belt 700 asit is being conveyed to the chute 822. It also prevents wind fromblowing the proppant 38 or silica dust 50 off the conveyor belt 700.Other shapes, for example, a wave or triangular shape, of the outer wall716 are acceptable so long as the conveyor belt 700 does not releasesilica dust 50 or proppant 38 through the outer wall 716 as it passesalong the rollers 708. The outer wall 716 may comprise a flat or roundedtop 720, much the same as the plurality of fingers 714. As can be seenin an embodiment shown in FIG. 11, for example, the plurality of fingers714 and the outer wall 716 are relatively the same height from the topsurface 702 of the conveyor belt 700. In the embodiment shown in FIG.11, the height of the plurality of partitions 712 can be between four toeight inches, including, for example, six inches. The substantiallysimilar height of the plurality of fingers 714 and the outer walls 716allows the conveyor belt 700 to be positioned as closely to the bottomportion 608 of each respective conveyor hopper 600 to minimize thedistance the proppant 38 has to fall as the proppant 38 flows from theplurality of conveyor hoppers 600 to the one or more conveyor belts 700.This distance between the plurality of conveyor hoppers 600, and the top718, 720 of the plurality of partitions 712 can be between zero and twoinches. With this negligible gap, the risk of production and release ofsilica dust 50 is reduced.

As shown in the embodiments of FIGS. 7A-7B and 8A-8D, the conveyor belt700 is positioned at or near the one or more controllable openings 610of the plurality of conveyor hoppers 600 to reduce risk of productionand release of silica dust 50 as proppant 38 flows from the plurality ofcontainers 900, to and through the plurality of conveyor hoppers 600,onto the one or more conveyor belts 700. In an embodiment, for example,the conveyor belt 700 is substantially enclosed. In an embodiment shownin FIGS. 12A and 12B, a curtain or curtains 1200 may be added to one ormore sides 1010A, 1010B of the conveyor 1000 to fully enclose the one ormore conveyor belts 700. The curtain or curtains 1200 may include tarps1202, steel panels 1204, or similar structures, that are removably orpermanently attached to the conveyor 1000 using fasteners 1206 such asbungee cords, rope, zip ties, bolts, screws, welding, or other materialadapted to be integral with or attached to the conveyor 1000. Thecurtain or curtains 1200 further protect the proppant 38 from the windat it is blowing across the well site 30, from the rain or precipitationat the well site 30, and from any incidental silica dust 50 or proppant38 that may spray from the conveyor belt 700, and thus further reducethe risk of the release of silica dust 50 into the air.

Similarly to the curtain or curtains 1200 of an embodiment shown in FIG.12A-12B, an embodiment of the present invention can include a blenderhopper cover 1208. Like the curtain or curtains 1200, the blender hoppercover 1208 may be added to the one or more outlets 826 of the chute 822or to the second end 1014 of the conveyor 1000 to fully enclose the pathto the blender hopper 810. The blender hopper cover 1208 may includetarps 1210, steel panels 1212, or similar structures, that are removablyor permanently attached to the chute 822 or conveyor 1000 usingfasteners 1214 such as bungee cords, rope, zip ties, bolts, screws,welding, or other material adapted to be integral with or attached tothe chute 822 or the conveyor 1000. The blender hopper cover 1208further protects the proppant 38 from the wind at it is blowing acrossthe well site 30, from the rain or precipitation at the well site 30,and from any incidental silica dust 50 or proppant 38 that may sprayfrom chute 822 or conveyor belt 700 as proppant 38 is deposited into theblender hopper 810, and thus further reduces the risk of the release ofsilica dust 50 into the air.

In an embodiment shown in FIG. 10A, for example, a first end portion 705can be parallel to the ground and positioned at the first end 1012 ofthe conveyor 1000. A second end portion 707 of the conveyor belt 700 canbe elevated relative to the first end portion 705 of the conveyor belt700 and positioned between the last respective container 900 on thesecond end 1014 of the conveyor 1000 and the chute 822, at an angle 805above parallel with respect to the ground. Rollers 708 positioned withinthe conveyor 1000 control the path the one or more conveyor belts 700travel. In an embodiment, for example, the conveyor belt 700 travels ina path that is level from the first end 1012 of the conveyor 1000 as theconveyor belt 700 passes beneath each of the plurality of conveyorhoppers 600 and containers 900 positioned thereabove, bends upward afterthe conveyor belt 700 has passed beneath the last container 900positioned on the conveyor 1000, and travels upward towards a second end1014 of the conveyor 1000, relative to a horizontal plane 1020, to thechute 822, where the conveyor belt 700 turns about a roller 708 andreturns toward the first end 1012 of the conveyor 1000. In anembodiment, for example, the second end 1014 of the conveyor 1000 can beelevated relative to the first end 1012 of the conveyor 1000 so thatproppant 38 may be deposited off of the end of the conveyor belt 700 viagravity feed 812 into the chute 822 for deposit into the blender hopper810.

In an embodiment of a method, for example, where a conveyor 1000 isholding all of the containers 900 it is designed to hold, as shown, forexample, in FIG. 12A, the conveyor belt 700 is level with the ground asit passes beneath each of the plurality of containers 900 positioned onthe conveyor 1000. As shown by the break-away portions of FIG. 8A, oncethe conveyor belt 700 passes the end of the last respective container900 positioned on the conveyor 1000, the conveyor belt 700 is directedby one or more rollers 708 in an upward direction towards the second end1014 of the conveyor 1000. This portion 802 of the conveyor belt 700 cantravel upwards at an angle 805 of approximately thirty to sixty degreeswith respect to a horizontal plane 1020 extending from the conveyor belt700 as it is level with the ground. The portion 802 of the conveyor belt700 that travels in an upward direction also passes through a shroud800, therein defining a shrouded portion 802 of the conveyor belt 700,as shown in FIGS. 8A-8B. The shrouded portion 802 is positioned betweena last respective container 900 on the conveyor 1000 and an inlet 824 ofthe chute 822 at an angle 805 of approximately 30 to 60 degrees from ahorizontal plane 1020 when the conveyor 1000 is level. At the second end1014 of the conveyor 1000, the one or more conveyor belts 700 turnsabout within the chute 822 that is substantially enclosed and travelsdownward towards a first end 1012 of the conveyor 1000. As shown in FIG.8B, as the conveyor belt 700 turns about, the proppant 38 is depositedinto a chute 822 that is enclosed by gravity feed 812. The proppant 38flows down the chute 822 and is deposited where the operator 806 ormachine directs the proppant 38 from the outlet 826 of the chute 822,but the chute 822 can be positioned to deposit proppant 38 into ablender hopper 810 at the well site 30, as shown in FIG. 8C.

In an embodiment, for example, shown in FIGS. 8D and 10C, the conveyorbelt 700 need not travel in an upward direction at the second end 1014of the conveyor 1000, but rather, may stay level, or travel in adownward path, if the conveyor 1000, the one or more conveyor belts 700,or the chute 822, is positioned to deposit proppant 38 into a blenderhopper 810 that is at or below the one or more conveyor belts 700, or ifthe chute 822 is positioned to deposit proppant 38 into a hole, forexample. This embodiment of the present invention may include the one ormore conveyor belts 700 traveling in a substantially level or downwardpath from the first end 1012 of the conveyor 1000 to the second end1014, underneath the plurality of conveyor hoppers 600, and depositingthe proppant 38 into a chute 822 or directly into a blender hopper 810without passing through a shrouded portion 802. In this embodiment, thechute 822 or blender hopper 810 is adapted or positioned to remain lowerto the ground than the top surface 702 of the conveyor belt 700 suchthat proppant 38 is deposited directly into either the chute 822 or theblender hopper 810 by gravity feed 812 as the conveyor belt 700 turnsabout around a roller 708. This embodiment, for example, provides thatthe one or more engines 710 and the controls 1017, if any, may need tobe moved from the second end 1014 of the conveyor 1000 to the first end1012 to accommodate the elimination of the shrouded portion 802 at thesecond end 1014. In this embodiment, the wheels 1016 of the conveyor1000 may also move to the first end 1012 of the conveyor 1000. Thisembodiment may also include a blender hopper cover 1208 and a pluralityof curtains 1200 to reduce the risk of production and release of silicadust 50 at the well site 30.

Referring to FIGS. 8A-8B, the shroud 800 is a box, tube, or containerstructure that substantially or completely encloses a the shroudedportion 802 of the conveyor belt 700 while it is traveling in an upwarddirection towards the second end 1014 of the conveyor 1000. The shroud800 can be a closed and elongated box having four sides 816A, 816B,816C, 816D, and a first end 818A and a second end 818B, each end beingopen to allow the conveyor belt to pass through. The sides 816A-D of theshroud 800 can include a plurality of steel panels bolted togetheraround the conveyor belt 700, and bolted to the conveyor at a first end818A, and bolted to the chute 822 at a second end 818B. The materialneed not be steel panels, but could also include a seamless steel box,or another structure made of a similar metal, plastic, cloth, tarp, orother sheets. The shroud 800 need not fully enclose the conveyor belt700. For example, the shroud 800 may include a tarp covering the topsurface 702 of the conveyor belt 700 having a plurality of partitions712, connected to the second end 1014 of the conveyor 1000 at the firstend 818A of the shroud 800 and the chute 822 at the second end 818B ofthe shroud 800, using fasteners 820 such as bungee cords, rope, zipties, or other connection means. Alternatively, the shroud 800 and chute822 may be integral with one another or fully connected by bolts,welding, or similar connection. The shroud 800 is adapted and positionedto reduce the risk of release of silica dust 50 associated with proppant38 as it is conveyed along the conveyor belt 700. The shroud 800 alsoprevents wind from blowing proppant 38 off of the conveyor belt 700, andrain from wetting the proppant 38 that may hinder the proppant 38 fromflowing properly.

The chute 822 is positioned at the second end 1014 of the conveyor 1000to receive the proppant 38 that is deposited by the conveyor belt 700via gravity feed 812. The chute 822 can be tube-shaped, but a chute 822may alternatively have a bottom portion and a top portion, for example.The chute 822 has an inlet 824 and one or more outlets 826, the inlet824 positioned to receive the second end 1014 of the conveyor 1000 andthe one or more conveyor belts 700 conveying proppant, and the one ormore outlets 826 of the chute 822 positioned to deposit proppant 38 intoa blender hopper 810 or another location on the well site 30. The chute822, like the shroud 800, is adapted and positioned to reduce the riskof release of silica dust 50 at the well site 30, but also to preventwind and rain from contacting the proppant 38. The chute 822, in oneembodiment, for example, is rotatably connected to the shrouded portion802 of the conveyor belt 700 such that an operator 806 or a machine canhold on to handles 823 attached to the chute 822 for positioning theopening or openings 826 of the chute 822 towards a blender hopper 810 oranother location at a well site 30, as shown in FIG. 8C. The chute 822may be controlled manually, by hydraulics, or by electronics via remoteor wireless control, or via the internet. If hydraulics are used, forexample, a plurality of hydraulic pressure hoses 819 can connect thechute 822 to the one or more engines 710 and controls 1017. Ifelectronics are used, for example, a plurality of wires 821 can be usedto connect the chute 822 to the one or more engines 710 and controls1017. Wireless connections are also contemplated. A person of skill inthe art would understand the various connections to engines 710 andcontrols 1017 available for powering the chute 822.

Well site operators also may be concerned about reducing the silica dust50 that may be produced or released as proppant 38 flows from the one ormore openings 826 of the chute 822 into the one or more blender hoppers810 of one or more blenders 36 at a well site 30. As shown in FIGS. 12Aand 12C, a blender hopper cover 1208 may be attached to, or positionedover the one or more openings 826 of the chute 822 to substantially orcompletely enclose the path between the one or more openings 826 of thechute 822 to the blender hopper 810. The blender hopper cover 1208 maybe adapted to connect more than one chute 822 into the same blenderhopper 810, for instance, where two conveyors 1000 of the presentinvention are positioned adjacent each other at a well site 30. Inanother embodiment, and as shown in FIG. 8D and FIG. 10C, for example,the blender hopper cover 1208 may be attached or positioned over thesecond end 1014 of the conveyor 1000 and the one or more conveyor belts700 to substantially enclose the path between the second end 1014 of theconveyor 1000 and the one or more conveyor belts 700 to the blenderhopper 810. In this embodiment, as well, the blender hopper cover may beadapted to connect more than one second end 1014 of the conveyor 1000and conveyor belt 700 to the same blender hopper 810, for instance,where two conveyors 1000 of the present invention are positionedadjacent each other at a well site 30. The blender hopper 1208 cover mayinclude tarps 1210, steel panels 1212, or panels of similar metals,plastic, or similar material. The blender hopper cover can bemanufactured to fit over or attach to the one or more openings 826 ofthe chute 822 and to the one or more blender hoppers 810 of the one ormore blenders 36 at a well site 30. The blender hopper cover 1208 mayinclude a window portion 1216 so the operator 806 may inspect theprogress of proppant 38 as it fills up the blender hopper 810. Theblender hopper 810 may also include electronic or wireless transmissionsignals to an operator 806 or machine to indicate a problem or that theblender hopper 810 is full. The blender hopper cover 1208 reduces therisk of production and release of silica dust 50 at the well site 30 asproppant flows out of an embodiment of a system to one or more blenders36.

As demonstrated in FIGS. 1, 3, 4, 5C, 6A-6C, 7A, and 8A-8C, anembodiment of the method of the present invention includes, for example,positioning 100 a plurality of containers 900 each having proppant 38for fracking contained therein onto a conveyor 1000 at a well site 30,the conveyor 1000 having a plurality of conveyor hoppers 600 and each ofthe plurality of conveyor hoppers 600 overlaying one or more conveyorbelts 700, each respective container 900 having a sealed top 904, 914 toreduce risk of release of silica dust 50 associated with proppant 38into the air. It further includes downwardly discharging 110 proppant 38from each respective container 900 of the plurality of containers 900,each respective container 900 further having inclined lower innerportions 922 and one or more outlets 924 positioned at a bottom 906 ofeach respective container 900, such that as proppant 38 flows by gravityfeed 812 along the inclined lower inner portions 922 to and through theone or more outlets 924, the risk of production and release of silicadust 50 into the air is reduced, and the respective container 900 issubstantially emptied of proppant 38. It further comprises funneling 120proppant 38 from the one or more outlets 924 of each of the plurality ofcontainers 900 through a plurality of conveyor hoppers 600, eachrespective conveyor hopper 600 having inclined sides 602 and one or morecontrollable openings 610 positioned adjacent and overlying the one ormore conveyor belts 700, such that as proppant 38 flows by gravity feed812 along the inclined sides 902 of each of the plurality of conveyorhoppers 600 through the one or more controllable openings 610 to theconveyor belt 700, the risk of production and release of silica dust 50into the air through the one or more controllable openings 610 isreduced. It further comprises receiving 130 proppant onto the one ormore conveyor belts 700, the conveyor belt 700 having a plurality ofpartitions 712 associated therewith, such that the plurality ofpartitions 712 are positioned to reduce risk of production and releaseof silica dust 50 into the air as proppant 38 contacts and is carried bythe conveyor belt 700. It further comprises conveying 140 proppant 38 onthe conveyor belt 700 to a chute 822, the conveyor belt 700 having afirst end portion 705 and a second end portion 707, the second endportion 707 of the conveyor belt 700 including a shrouded portion 802that has a shroud 800 substantially enclosing the conveyor belt 700 andpositioned to substantially reduce risk of release of silica dust 50associated with proppant 38 into the air as the proppant 38 is conveyedthrough the shrouded portion 802. It further comprises depositing 150the proppant 38 from the second end portion 707 of the conveyor belt 700to the chute 822 for depositing into a blender hopper 810 or anotherlocation at the well site 30.

After proppant 38 has been discharged from a respective container 900 ofthe plurality of containers 900, the method further can include removing160 the respective container 900 from the conveyor 1000 for replacementwith another respective container 900 filled with proppant 38, such thatthe conveyor belt 700 continuously conveys proppant 38 at the well site30 from the plurality of containers 900 to the blender 36. An operator806 or machine may use a forklift 34, crane 35, or other heavy machineryto move containers 900 at the well site 30.

A flow gate 932 and inclined lower inner portions 922 of each respectivecontainer 900 help to control the flow of proppant 38 from the container900 and thereby reduce the risk of production of silica dust 50 from thecontainer 900. An embodiment of the method further can includecontrolling 170 the rate of proppant 38 as it flows through the one ormore outlets 924 of each respective container 900 by one or more flowgates 932 positioned at the one or more outlets 924 to reduce the riskof production and release of silica dust 50 into the air through the oneor more outlets 924. The flow gate 932 can be connected to an actuator502 thereby to enhance opening and closing of the flow gate 932. Theactuator 502 may be optionally controlled by hydraulics or electronics.If hydraulics are used, for example, a plurality of hydraulic pressurehoses 503 can connect the actuator 502 to the one or more engines 710and controls 1017. If electronics are used, for example, a plurality ofwires 505 can be used to connect the actuator 502 to the one or moreengines 710 and controls 1017. Wireless connections are alsocontemplated. A person of skill in the art would understand the variousconnections to engines 710 and controls 1017 available for powering theactuator 502. The inclined lower inner portions 922 of each respectivecontainer 900 are inclined inwardly from inner walls of the respectivecontainer toward a bottom of the container at an angle 928 of about 31degrees to about 37 degrees relative to a horizontal plane 920 of thebottom of each respective container 900 when each respective container900 is level. This angle 928 helps to empty the container 900 ofproppant 38 to reduce the risk of silica exposure for well site workers.

A hopper gate 612, a hopper gate actuator 613, and a plurality ofinclined sides 602 of each respective conveyor hopper 600 help tocontrol the flow of proppant 38 from each respective conveyor hopper 600and thereby reduce the risk of production and release of silica dust 50from the conveyor hopper 600. The method can also further includecontrolling 180 the rate of proppant 38 as the proppant 38 flows fromthe one or more controllable openings 610 of each respective conveyorhopper 600 to reduce the risk of production and release of silica dust50 into the air through the one or more controllable openings 610, theone or more controllable openings 610 having a hopper gate 612 connectedto a hopper gate actuator 613. The hopper gate actuator 613 isoptionally controlled by hydraulics or electronics to enhance openingand closing of the one or more controllable openings 610 via the hoppergate 612. If hydraulics are used, for example, a plurality of hydraulicpressure hoses 614 can connect the hopper gate actuator 613 to the oneor more engines 710 and controls 1017. If electronics are used, forexample, a plurality of wires 616 can be used to connect the hopper gate612 to the one or more engines 710 and controls 1017. Wirelessconnections are also contemplated. A person of skill in the art wouldunderstand the various connections to engines 710 and controls 1017available for powering the hopper gate actuator 613. The plurality ofinclined sides 602 can include, for example, a pair of short sides604A1, 604A2 representing the depth of the conveyor hopper 600, and apair of long sides 604B1, 604B2 representing the length of the conveyorhopper 600. The plurality of inclined sides 602 are positioned whereinpair of short sides 604A1, 604A2 have a funnel angle 605A or slope ofapproximately 35 to 40 degrees relative to a horizontal plane, and apair of long sides 604B1, 604B2 have a funnel angle 605B or slope ofapproximately 28 to 33 degrees relative to a horizontal plane, in orderto maximize the capacity of the conveyor hopper 600 and the flow ofproppant 38 from the conveyor hopper 600, and to reduce the risk ofproduction and release of silica dust 50 from each respective conveyorhopper 600.

In another embodiment, for example, and as illustrated in FIGS. 1, 3, 4,5C, 6A-6C, 7A, and 8D, the method can include utilizing a plurality ofcontainers 900 having proppant 38 for fracking contained therein, eachrespective container 900 having an outlet 924 and a sealed top 904, 914,the sealed top 904, 914 positioned to reduce risk of release of silicadust 50 associated with proppant 38 from the sealed top 904, 914 of eachrespective container 900. It further comprises positioning 100 eachrespective container 900 on a conveyor 1000 at a well site 30, theconveyor 1000 having a plurality of conveyor hoppers 600 and each of theplurality of conveyor hoppers 600 having one or more controllableopenings 610 that is in fluid communication with a conveyor belt 700that underlies the conveyor 1000 to reduce risk of production andrelease of silica dust 50 associated with proppant 38 as the proppant 38flows from each respective container 900. It further comprisesdownwardly discharging 110 the proppant 38 from each respectivecontainer 900 through each respective controllable opening 610 of eachrespective conveyor hopper 600 onto the conveyor belt 700, the conveyorbelt 700 having a first end portion 705, a second end portion 707, and aplurality of partitions 712 associated therewith, the plurality ofpartitions 712 of the conveyor belt 700 positioned to enhance reductionof production and release of silica dust 50 as the proppant 38 contactsand is carried by the conveyor belt 700. It further comprises conveying240 the proppant to one or more blender hoppers 810, and depositing 250the proppant 38 into the one or more blender hoppers 810 by gravity feed812.

The method also can include, for example, removing 160 each respectivecontainer 900 that has been substantially emptied of proppant 38 fromthe conveyor 1000 at the well site 30 with a forklift 34 for replacementwith a second respective container 900 filled with proppant 38 forfracking contained therein such that the conveyor belt 700 iscontinuously conveying proppant 38 when in operation to the chute 822.

The method also can include, for example, controlling 170 the rate ofproppant 38 flowing from each respective container 900 using a flow gate932 positioned at the one or more outlets 924 of each respectivecontainer 900 to reduce risk of production and release of silica dust 50associated with proppant 38 into the air as proppant 38 flows out of theone or more outlets 924, as shown in FIG. 5B.

The method also can include, for example, controlling 180 the rate ofproppant 38 downwardly flowing from each respective conveyor hopper 600using a hopper gate 612 with a hopper gate actuator 613 positioned atthe one or more controllable openings 610 of each respective conveyorhopper 600, and optionally controlling the hopper gate actuator 613 byhydraulics or electronics to enhance opening and closing of the hoppergate 612 to reduce risk of production and release of silica dust 50associated with proppant 38 into the air as proppant 38 flows out of theone or more controllable opening 610, as shown in FIG. 11 and FIG. 7A.If hydraulics are used, for example, a plurality of hydraulic pressurehoses 614 can connect the hopper gate actuator 613 to the one or moreengines 710 and controls 1017. If electronics are used, for example, aplurality of wires 616 can be used to connect the hopper gate 612 to theone or more engines 710 and controls 1017. Wireless connections are alsocontemplated. A person of skill in the art would understand the variousconnections to engines 710 and controls 1017 available for powering thehopper gate actuator 613.

The method also can include, for example, positioning 245 a shroud 800over a portion 802 of the second end 707 of the conveyor belt 700thereby to define a shrouded portion 802, the shrouded portion 802positioned between the last respective container 900 on the conveyor1000 and the chute 822 at an angle 805 of approximately 30 to 60 degreesfrom a horizontal plane 1020 when the conveyor is level. The shroud 800substantially encloses the one or more conveyor belts 700 to reduce therisk of release of silica dust 50 associated with proppant 38 in theair.

The method also can include, for example, positioning 102 each of theplurality of containers 900 side-by-side on the conveyor 1000.

The method also can include, for example, positioning 104 the pluralityof containers 900 adjacent each other on the conveyor 1000, wherein eachof the plurality of partitions 712 of the conveyor belt 700 extendupwardly from a top surface 702 of the conveyor belt 700 toward theconveyor hopper 600 when positioned to underlie the conveyor hopper 600and each of the plurality of fingers 714 is spaced-apart from anotherone of the plurality of fingers 714 so that the top surface 702 of theconveyor belt 700 guidingly receives the proppant 38 thereon and betweenthe plurality of partitions 714.

An embodiment of the system of the present invention can include, forexample, a plurality of containers 900 each adapted to have proppant 38for fracking contained therein, each respective container 900 having asealed top 904, 914 to reduce risk of release of silica dust 50associated with proppant 38 into the air when positioned therein. Eachrespective container 900 has interior portions 922 inclined toward anoutlet 924 at a bottom 916 of each respective container 900 to reducerisk of production and release of silica dust 50 associated withproppant 38 as the proppant 38 flows from each respective container 900until each respective container 900 is substantially empty.

The system further can include a conveyor 1000 positioned at a well site30 and to receive each respective container 900 of the plurality ofcontainers 900, the conveyor 1000 having one or more conveyor hoppers600 that align closely with each respective outlet 924 of the pluralityof containers 900 to reduce risk of production and release of silicadust 50 into the air, each of the one or more respective conveyorhoppers 600 having a lower portion 608 including an opening 610, suchthat when proppant 38 downwardly flows through each respective outlet924 of each respective container 900 of the plurality of containers 900when positioned therein, the proppant 38 passes to and through theopening 610 of each of the one or more respective conveyor hoppers 610.

The system further can include one or more conveyor belts 700 positionedto underlie the one or more conveyor hoppers 600 to receive proppant 38as the proppant 38 passes to and through the opening 610 of each of theone or more respective conveyor hoppers 600, the conveyor belt 700having a first end 705, a second end 707, and a plurality of partitions714 associated therewith, such that the plurality of partitions 714 arepositioned to reduce risk of production and release of silica dust 50 asproppant 38 contacts and is carried by the conveyor belt 700.

The system further can include a shroud 800 positioned to overlie aportion of the second end 705 of the conveyor belt 700 thereby to definea shrouded portion 802 of the conveyor belt 700, the shroud 800substantially enclosing the shrouded portion 802 as the conveyor belt700 conveys proppant 38 when positioned thereon from the plurality ofcontainers 900 to reduce risk of release of silica dust 50 associatedwith proppant 38 into the air from the shrouded portion 802.

The system further can include a chute 822 having an inlet 824positioned to receive the second end 707 of the conveyor belt 700conveying proppant 38 and one or more outlets 826 positioned such thatas proppant 38 is deposited into the chute 822 by gravity feed 812,proppant 38 flows out of the one or more outlets 826 to a blender hopper810 or other location at the well site 30.

The system also further can include a blender hopper cover 1208positioned to reduce risk of production and release of silica dust 50 asproppant 38 flows between the one or more outlets 826 of the chute 822and the one or more blender hoppers 810 of the one or more blenders 36at a well site 30.

The system also further can include a forklift 34 positioned at a wellsite 30 to load and unload each respective container 900 onto and off ofthe conveyor 1000 by one or more slots 901, wherein each of theplurality of containers 900 has one or more slots 901 positionedadjacent a bottom portion 906 of the respective container 900.

The system also further can include a plurality of curtains 1200positioned on or adjacent the conveyor 1000 to reduce risk of productionand release of silica dust 50 as proppant 38 flows from the plurality ofconveyor hoppers 600 to the one or more conveyor belts 700.

Another embodiment of the system, for example, can include a pluralityof containers 900 each adapted to have proppant 38 for frackingcontained therein, each respective container 900 having a sealed top904, 914 to reduce risk of release of silica dust 50 associated withproppant 38 into the air when positioned therein. Each respectivecontainer 900 has interior portions 922 inclined toward an outlet 924 ata bottom 906 of each respective container to reduce risk of productionand release of silica dust 50 associated with proppant 38 as theproppant 38 flows from each respective container 900 until eachrespective container 900 is substantially empty.

The system further can include a conveyor 1000 positioned at a well site30 and to receive each respective container 900 of the plurality ofcontainers 900, the conveyor 1000 having one or more conveyor hoppers600 that align closely with each respective outlet 924 of the pluralityof containers 900 to reduce risk of production and release of silicadust 50 into the air, each of the one or more respective conveyorhoppers 600 having a lower portion 608 including an opening 610, suchthat when proppant 38 downwardly flows through each respective outlet924 of each respective container 900 of the plurality of containers 900when positioned therein, the proppant 38 passes to and through theopening 610 of each of the one or more respective conveyor hoppers 600.

The system further can include one or more conveyor belts 700 positionedto underlie the one or more conveyor hoppers 600 to receive proppant 38as the proppant 38 passes to and through the opening 610 of each of theone or more respective conveyor hoppers 600, the conveyor belt 700having a first end 705, a second end 707, and a plurality of partitions714 associated therewith, such that the plurality of partitions 714 arepositioned to reduce risk of production and release of silica dust 50 asproppant 38 contacts and is carried by the conveyor belt 700.

As shown in FIG. 8D, the system further can include a blender hopper 810positioned to underlie the second end 707 of the conveyor belt 700conveying proppant 38 such that proppant 38 is deposited into theblender hopper 810 by gravity feed 812.

As shown in FIG. 12D, the system also further can include a blenderhopper cover 1208 positioned to reduce risk of production and release ofsilica dust 50 as proppant 38 flows between the one or more outlets 808of the chute 822 and the one or more blender hoppers 810 of the one ormore blenders 36 at a well site 30.

The system also further can include a forklift 34 positioned at a wellsite 30 to load and unload each respective container 900 onto and off ofthe conveyor 1000 by one or more slots 901, wherein each of theplurality of containers 900 has one or more slots 901 positionedadjacent a bottom portion 916 of the respective container 900.

The system also further can include a plurality of curtains 1200positioned on or adjacent the sides of the conveyor 1000 to reduce riskof production and release of silica dust 50 as proppant 38 flows fromthe plurality of conveyor hoppers 600 to the conveyor belt 700.

The owner of the present application conducted experiments to determinethe amount of reduction to respirable crystalline silica particles usingan embodiments of method and systems relative to conventional pneumaticdelivery. The testing was carried out by Weston Solutions, Inc. ofLakewood, Colo. The tests were based on samples collected for personalbreathing zone samples to assess likely employee exposure to respirablecrystalline silica by job category at a well site. Personal breathingzone samples were collected in order to compare the results to thosefound in the NIOSH study.

Personal breathing zone samples were collected using conventionalindustrial hygiene techniques. A filter cassette and a particle sizingcyclone were affixed to each monitored worker's collar or shoulder seamwithin ten inches of the mouth and nose. A Tygon™ tube conducted airflowfrom the breathing zone collection device to a hygiene sampling pumpworn in a pouch affixed to a belt around the worker's waist. Sample flowrates were determined before and after sampling using a primary standardflow calibrator.

Sixteen personal breathing zone monitoring samples were collected overthree days, and during four work shifts. Three of the sixteen samplesexceeded the OSHA Permissable Exposure Limit (“PEL”) for respirable dustcontaining silica, or about 19%. These were notably fewer results fromthis assessment above the PEL than in the NIOSH study cited in theSilica Hazard Alert, discussed in the background section, where 51.4% ofbreathing zone samples exceeded the PEL. No breathing zone sample inthis assessment exceeded the PEL by more than a factor of five, whereassix breathing zone exposure monitoring results of forty total from aMinot area well fracture job using pneumatic sand delivery exceeded thePEL by a factor of ten or more. Four of the sixteen personal breathingzone samples, or 25%, exceeded the NIOSH Recommended Exploded Limit(“REL”). On a pneumatic delivery fracture job near Minot, twenty-four ofthe forty breathing zone samples, or 60%, exceeded the NIOSH REL. Thatresult was somewhat less than in the NIOSH study where 68.5% of allsamples exceeded the REL. In summary, the geometric mean result forbreathing zone samples from t-belt operators in the NIOSH study was0.327 mg/m³ as the REL, whereas the geometric mean exposure for sandworkers in this assessment was 0.0874 mg/m³, a roughly four-foldreduction.

This application is related to and claims priority to, and the benefitof, U.S. Provisional Application No. 62/012,160, filed Jun. 13, 2014,titled “Process and Apparatus for Reducing Silica Exposure During theDelivery of Proppants to a Mine,” U.S. Provisional Application No.62/014,479, filed on Jun. 19, 2014, titled “System and Methods forReducing Silica Exposure at a Well Site,” and U.S. ProvisionalApplication No. 62/114,614, filed Feb. 11, 2015, titled “Methods andSystems to Transfer Proppant for Fracking with Reduced Risk ofProduction and Release of Silica Dust at a Well Site,” each of which areincorporated herein in their entireties by reference.

The foregoing disclosure and description of the invention isillustrative and explanatory of the embodiments of the invention.Various changes in the details of the illustrated embodiments can bemade within the scope of the appended claims without departing from thetrue spirit of the invention. The embodiments of the present inventionshould only be limited by the following claims and their legalequivalents.

1. A method of transferring proppant for fracking to reduce risk ofproduction and release of silica dust at a well site, the methodcomprising: positioning a plurality of containers each having proppantfor fracking contained therein onto a conveyor at a well site, theconveyor having a plurality of conveyor hoppers and each of theplurality of conveyor hoppers overlaying a conveyor belt, eachrespective container having a sealed top to reduce the risk of releaseof silica dust associated with proppant into the air; downwardlydischarging proppant from each respective container of the plurality ofcontainers, each respective container further having inclined lowerinner portions and one or more outlets positioned at a bottom of eachrespective container, such that as proppant flows by gravity feed alongthe inclined lower inner portions to and through the one or moreoutlets, risk of production and release of silica dust into the air isthereby reduced, and the respective container is substantially emptiedof proppant; funneling proppant from the one or more outlets of each ofthe plurality of containers through the plurality of conveyor hoppers,each respective conveyor hopper having a plurality of inclined sideportions and one or more controllable openings positioned adjacent andoverlying the conveyor belt, such that as proppant flows by gravity feedalong the plurality of inclined side portions of each of the pluralityof conveyor hoppers through the one or more controllable openings to theconveyor belt, risk of production and release of silica dust into theair through the one or more controllable openings is thereby reduced;receiving proppant onto the conveyor belt, the conveyor belt having aplurality of partitions associated therewith, such that the plurality ofpartitions are positioned to reduce the risk of production and releaseof silica dust into the air as the proppant contacts and is carried bythe conveyor belt; conveying proppant on the conveyor to a chute, theconveyor belt having a first end portion and a second end portion, thesecond end portion of the conveyor belt including a shrouded portionthat has a shroud substantially enclosing the conveyor belt andpositioned to substantially reduce the risk of release of silica dustassociated with proppant into the air as the proppant is conveyedthrough the shrouded portion; and depositing the proppant from thesecond end portion of the conveyor into the chute.
 2. The method ofclaim 1, further comprising: after proppant has been discharged from arespective container of the plurality of containers, removing therespective container from the conveyor for replacement with anotherrespective container filled with proppant, such that the conveyor beltcontinuously conveys proppant at the well site from the plurality ofcontainers to the chute.
 3. The method of claim 1, further comprising:controlling the rate of proppant as it flows through the one or moreoutlets of each respective container using a flow gate positioned at theone or more outlets to reduce the risk of production and release ofsilica dust into the air through the one or more outlets, the flow gateoptionally controlled by hydraulics or electronics to enhance openingand closing of the flow gate, wherein the plurality of conveyor hoppersare positioned side-by-side and are substantially aligned with theplurality of containers.
 4. The method of claim 1, wherein the inclinedlower inner portions of each respective container are inclined inwardlyfrom inner walls of the respective container toward a bottom of thecontainer at an angle of about 31 degrees to about 37 degrees relativeto a horizontal plane of the bottom of each respective container wheneach respective container is level.
 5. The method of claim 1, furthercomprising: controlling the rate of proppant as it flows from the one ormore controllable openings of each respective conveyor hopper to reducethe risk of production and release of silica, dust into the air throughthe one or more controllable openings, the one or more controllableopenings having a hopper gate and a hopper gate actuator, the hoppergate actuator optionally controlled by hydraulics or electronics toenhance opening and closing of the one or more controllable openings;and positioning the plurality of inclined side portions, wherein theplurality of inclined side portions further comprise a pair of shortside portions having a funnel angle or slope of approximately 35 to 40degrees relative to a horizontal plane, and a pair of long side portionshaving a funnel angle or slope of approximately 28 to 33 degreesrelative to a horizontal plane, to maximize the capacity of the conveyorhopper and the flow of proppant from the conveyor hopper.
 6. The methodof claim 1, wherein the shrouded portion is positioned between a lastrespective container on the conveyor and the chute at an angle ofapproximately 30 to 60 degrees from a horizontal plane when the conveyoris level.
 7. (canceled)
 8. The method of claim 1, wherein the pluralityof partitions comprises a plurality of fingers, each respective fingerextending, upwardly from the conveyor belt and spaced apart from anotherrespective finger, and a plurality of side walls, each respective sidewall extending upwardly from and positioned near an outside edge of theconveyor belt, to reduce the production and release of silica dust asproppant received and conveyed on the conveyor belt.
 9. The method ofclaim 8, wherein the plurality of containers are positioned adjacenteach other on the conveyor, and wherein each of a plurality ofpartitions of the conveyor belt connect to and extend upwardly from atop surface of the conveyor belt toward the conveyor hopper whenpositioned to underlie the conveyor hopper, and each of the plurality offingers is spaced-apart from another one of the plurality of lingers sothat the top surface of the conveyor belt receives the proppant thereonand between the plurality of partitions.
 10. A method for reducing riskof production and release of silica dust at a well site during, thetransport of proppant for fracking, the method comprising: utilizing aplurality of containers having proppant for fracking contained therein,each respective container having an outlet and a sealed top, the sealedtop positioned to reduce risk of release of silica dust associated withproppant from the sealed top of each respective container; positioningeach respective container on a conveyor at the well site, the conveyorhaving a plurality of hoppers and each of the plurality of hoppershaving an opening that is in fluid communication with a conveyor beltthat underlies the conveyor to reduce risk of production and release ofsilica dust associated with proppant as the proppant flows from eachrespective container; downwardly discharging the proppant from eachrespective container through each respective opening of each respectivehopper onto the conveyor belt, the conveyor belt having a first endportion, a second end portion, and a plurality of partitions associatedtherewith, the plurality of partitions of the conveyor belt positionedto reduce risk of production and release of silica dust as the proppantcontacts and is carried by the conveyor belt; conveying the proppant toa blender hopper; and depositing the proppant into the blender hopper bygravity feed.
 11. The method of claim 10, wherein each of the pluralityof containers has a plurality of inclined lower inner portions inclinedat an angle of about 31 degrees to about 37 degrees relative to ahorizontal plane of a bottom of each respective container when eachrespective container is level, such that proppant downwardly flows bygravity feed along the plurality of inclined lower inner portions toreduce risk of production and release of silica dust associated withproppant into the air at the outlet of each respective container untileach respective container is substantially empty of proppant.
 12. Themethod of claim 10, further comprising: after proppant has beendownwardly discharged from each respective container, removing eachrespective container from the conveyor at the well site with a forkliftfor replacement with a second respective container filled with proppantfor fracking contained therein such that the conveyor belt iscontinuously conveying proppant to the chute.
 13. The method of claim10, further comprising: controlling the rate of proppant flowing fromeach respective container using a flow gate positioned at the outlet ofeach respective container to reduce risk of production and release ofsilica dust associated with proppant into the air as proppant flows outof the outlet; and optionally controlling the flow gate by hydraulics orelectronics to enhance opening and closing of the flow gate to reducerisk of production and release of silica dust associated with proppantinto the air as proppant flows out of the outlet.
 14. The method ofclaim 10, further comprising: controlling the rate of proppantdownwardly flowing from each respective hopper using a hopper gate and ahopper gate actuator positioned at the controllable opening of eachrespective hopper, wherein the plurality of hoppers are positionedside-by-side and are substantially aligned with the plurality ofcontainers; and optionally controlling the hopper gate actuator byhydraulics or electronics to enhance opening and closing of the hoppergate to reduce risk of production and release of silica dust associatedwith proppant into the air as proppant flows out of the controllableopening.
 15. The method of claim 10, further comprising positioning ashroud over a portion of the second end portion of the conveyor beltthereby to define a shrouded portion, the shroud substantially enclosingthe shrouded portion to reduce the risk of release of silica dustassociated with the proppant into the air.
 16. The method of claim 10,wherein each of the plurality of containers is positioned side-by-sideon the conveyor, and a top surface of the conveyor is substantiallyaligned with a plane of a respective top portion of each hopper of theplurality of hoppers.
 17. The method of claim 10, wherein the pluralityof containers are positioned adjacent each other on the conveyor, andwherein each of the plurality of partitions of the conveyor belt extendupwardly from a top surface of the conveyor belt toward the plurality ofhoppers when positioned to underlie the plurality of hoppers and each ofthe plurality of fingers is spaced-apart from another one of theplurality of fingers so that the top surface of the conveyor beltreceives the proppant thereon and between the plurality of partitions.18. A system to convey proppant for fracking from a plurality ofcontainers to a chute thereby to reduce risk of production and releaseof silica dust at a well site, the system comprising: the plurality ofcontainers each adapted to have proppant for fracking contained therein,each respective container having a sealed top to reduce risk of releaseof silica dust associated with proppant into the air when positionedtherein, each respective container further having interior portionsinclined toward an outlet at a bottom of each respective container toreduce risk of production and release of silica dust associated withproppant as the proppant flows from each respective container until eachrespective container is substantially empty; a conveyor positioned atthe well site and to receive each respective container of the pluralityof containers, the conveyor having one or more conveyor hoppers thatalign closely with each respective outlet of the plurality of containersto reduce risk of production and release of silica dust into the air,each of the one or more respective conveyor hoppers having a lowerportion including an opening, such that when proppant downwardly flowsthrough each respective outlet of each respective container of theplurality of containers when positioned therein, the proppant passes toand through the opening of each of the one or more respective conveyorhoppers; a conveyor belt positioned to underlie the one or more conveyorhoppers to receive proppant as the proppant passes to and through theopening of each of the one or more respective conveyor hoppers, theconveyor belt having a first end, a second end, and a plurality ofpartitions associated therewith, such that the plurality of partitionsare positioned to reduce risk of production and release of silica dustas proppant contacts and is carried by the conveyor belt; a shroudpositioned to overlie a portion of the second end of the conveyor beltthereby to define a shrouded portion of the conveyor belt, the shroudsubstantially enclosing the shrouded portion as the conveyor beltconveys proppant when positioned thereon from the plurality ofcontainers to reduce risk of release of silica dust associated withproppant into the air from the portion; and the chute having an inletpositioned to receive the second end of the conveyor belt conveyingproppant and one or more outlets positioned such that as proppant isdeposited into the chute by gravity feed, proppant flows out of the oneor more outlets to one or more blenders or other location at the wellsite.
 19. The system of claim 18, wherein the interior walls inclinedtoward an outlet at the bottom of each respective container are inclinedat an angle of about 31 degrees to about 37 degrees relative to ahorizontal plane of a bottom of each respective container when eachrespective container is level.
 20. The system of claim 18, wherein eachrespective conveyor hopper of the plurality of conveyor hoppers has aplurality of inclined side portions, and wherein the plurality ofinclined side portions further comprise a pair of short side portionshaving a funnel angle or slope of approximately 35 to 40 degreesrelative to a horizontal plane, and a pair of long side portions havinga funnel angle or slope of approximately 28 to 33 degrees relative to asecond horizontal plane, to maximize the capacity of the conveyor hopperand the flow of proppant from the conveyor hopper, and to reduce therisk of production and release of silica dust associated with proppantas it flows along the plurality of inclined side portions, and whereinthe plurality of conveyor hoppers are positioned side-by-side and aresubstantially aligned with the plurality of containers.
 21. The systemof claim 18, further comprising a blender hopper cover positioned toreduce risk of production and release of silica dust as proppant flowsbetween the one or more outlets of the chute and one or more blenderhoppers of the one or more blenders at the well site.
 22. The system ofclaim 18, wherein each of the plurality of containers has one or moreslots positioned adjacent a bottom portion of the respective container,and the system further comprising a forklift positioned at the well siteto load and unload each respective container onto and off of theconveyor by the one or more slots.
 23. The system of claim 18, whereinthe conveyor comprises a plurality of curtains positioned to reduce riskof production and release of silica dust as proppant flows from theplurality of conveyor hoppers to the conveyor belt.
 24. The system ofclaim 18, wherein the plurality of partitions comprises a plurality offingers, each respective finger connected to, and extending upwardlyfrom the conveyor belt and spaced apart front another respective finger,and a plurality of side walls, each respective side wall connected toand extending upwardly from, and positioned at or near, an outside edgeof the conveyor belt, to reduce the production and release of silicadust as proppant is received and conveyed on the conveyor belt.
 25. Thesystem of claim 18, further comprising: a flow gate positioned at theoutlet of each respective container to control the downward flow ofproppant through the outlet to reduce the risk of production and releaseof silica dust associated with proppant into the air through the outlet,and wherein each of the plurality of partitions of the conveyor beltextend upwardly from a top surface of the conveyor belt toward a hopperof the one or more conveyor hoppers hopper when positioned to underliethe hopper of the one or more conveyor hoppers and each of the pluralityof fingers is spaced-apart from another one of the plurality of fingersso that the top surface of the conveyor belt receives the proppantthereon and between the plurality of partitions when the proppantdischarges from the hopper of the one or more conveyor hoppers.
 26. Asystem to convey proppant for fracking from a plurality of containers toone or more blender hoppers thereby to reduce risk of production andrelease of silica dust at a well site, the system comprising: theplurality of containers each adapted to have proppant for frackingcontained therein, each respective container having a sealed top toreduce risk of release of silica dust associated with proppant into theair when positioned therein, each respective container further havinginterior portions inclined toward an outlet at a bottom of eachrespective container to reduce risk of production and release of silicadust associated with proppant as the proppant flows from each respectivecontainer until each respective container is substantially empty; aconveyor positioned at the well site and to receive each respectivecontainer of the plurality of containers; the conveyor having one ormore conveyor hoppers that align closely with each respective outlet ofthe plurality of containers to reduce risk of production and release ofsilica dust into the air, each of the one or more respective conveyorhoppers having a lower portion including an opening, such that whenproppant downwardly flows through each respective outlet of eachrespective container of the plurality of containers when positionedtherein, the proppant passes to and through the opening of each of theone or more respective conveyor hoppers; a conveyor belt positioned tounderlie the one or more conveyor hoppers to receive proppant as theproppant passes to and through the opening of each of the one or morerespective conveyor hoppers, the conveyor belt having a first end, asecond end, and a plurality of partitions associated therewith, suchthat the plurality of partitions are positioned to reduce risk ofproduction and release of silica dust as proppant contacts and iscarried by the conveyor belt; the one or more blender hoppers having aninlet positioned to receive the second end of the conveyor beltconveying proppant such that proppant is deposited into the one or moreblender hoppers by gravity feed.
 27. The system of claim 26, wherein theinterior portions inclined toward an outlet at the bottom of eachrespective container are inclined at an angle of about 31 degrees toabout 37 degrees relative to a horizontal plane of the bottom of eachrespective container when each respective container is level.
 28. Thesystem of claim 26, wherein each respective conveyor hopper of theplurality of conveyor hoppers has a plurality of inclined side portions,and wherein the plurality of inclined side portions further comprise apair of short side portions having a funnel angle or slope ofapproximately 35 to 40 degrees relative to a horizontal plane, and apair of long side portions having a funnel angle or slope ofapproximately 28 to 33 degrees relative to a second horizontal plane, tomaximize the capacity of the conveyor hopper and the flow of proppantfrom the conveyor hopper, and to reduce the risk of production andrelease of silica dust associated with proppant as it flows along theplurality of inclined side portions, and wherein the plurality ofconveyor hoppers are positioned side-by-side and are substantiallyaligned with the plurality of containers.
 29. The system of claim 26,further comprising a blender hopper cover positioned to reduce risk ofproduction and release of silica dust as proppant flows between one ormore outlets of a chute and the one or more blender hoppers of one ormore blenders at the well site.
 30. The system of claim 26, wherein eachof the plurality of containers has one or more slots positioned adjacenta bottom portion of the respective container, and the system furthercomprising a forklift positioned at a well site to load and unload eachrespective container onto and off of the conveyor by the one or moreslots.
 31. The system of claim 8, wherein the plurality of containersare positioned in a side-by-side arrangement on the conveyor and aheight of the plurality of side walls is substantially similar to aheight of the plurality of fingers.